With the increase of substance abuse over the world, substance abuse e.g. ketamine and methamphetamine related voiding dysfunction is becoming an important medical problem. However, while the clinical manifestation of the condition is becoming better defined, the underlying pathophysiology is still poorly understood. Moreover, majority of the current treatment is just based on the experience on some small case series and there is no treatment data for larger patient sample or standard recommended treatment in the literature. In order to improve the management of this condition, investigators have formulated a treatment protocol based on the current literatures on the management of voiding dysfunction and also a similar condition, interstitial cystitis / painful-bladder syndrome (IC/PBS). The protocol basically consists of the following modalities: * Basic information and education on the condition, principle of treatment and psychosocial support. * First line treatment will include a course of oral anti-inflammatory drugs (for the control of the inflammation process and pain) and anticholinergic agents (for the irritative urinary symptoms). * If these simple oral medication are found to be not effective, then further treatment will include other oral medications, such as amitriptyline and gabapentin, and some drugs that directly applied into the bladder cavity (hyaluronate) or bladder muscle (botulinum toxin). * For those patients with intractable symptoms and failed all the above treatments, surgical treatment (hydrodistension, augmentation cystoplasty) will be discussed. The purpose of this research is to assess the effectiveness of the above treatment protocol in the management of substance induced voiding dysfunction and also assess any possible adverse events related to the usage of the drugs.